I don't know much about OCI driver. But i guess similar to other JDBC drivers, it will be packaged in a jar (which you can place in %JBOSS_HOME%/server/< serverName>/lib folder) and maybe some specific parameters/connection url that needs to be used in the datasource configuration (through *-ds.xml file).
The JCA forum http://www.jboss.com/index.html?module=bb&op=viewforum&f=136 might be more suitable for this question
I know how to configure a ds.xml file. However, Oracle OS authentication is different in that all that you need to do from a command line is this:
Oracle Client is then smart enough to look at your environment and see if there is an SID configured. If there is, it passes you to the Oracle DB.
So, I just do not know what, if any, username and password to use.
You might have to go into the Oracle admin console and add a username and password specifically so that you can use it in *-ds.xml.
I run into similar issues with PostgreSQL on Linux where by default PostgreSQL login is done according to the user's Linux account name. Going into PostgreSQL and either adding passwords to user accounts or adding new accounts solves this (and also telling PostgreSQL to accept login using username and password, instead of going by Linux account name).
Oracle OS authentication allows you to add a user that can access the database from the OS level, instead of a database-level user.
This OS user would most definitely have a password.